Cls 2214 Clinical Micro Exam 2

Front 1

Where are anaerobes normal flora

Back 1

1- skin and mucous membranes
2- oral cavity and URT
3- urethra
4- vagina
5- intestinal tract

Front 2

For pathogenic anaerobes,
name the genus that is the most abundant group of bacteria in the intestinal tract and oral cavity

Back 2

Bacteroides Fragilis group
- composes 43% of all clinical ANA isolates and 30% of all the bacteria in feces

Front 3

list 5 groups of anaerobes that together account for 2/3rds of infections.

Back 3

Bacteroides fragilis
Porphyromonas and Prevotella
Fusobacteruim nucleatum
Clostridium perfringens
ANA cocci

Front 4

Give the ratio of anaerobes to aerobes in the G.I. tract

Back 4

1000 to 1

Front 5

give the percentage of anaerobic bacteria found in the oral and nasal regions.

Back 5

90%

Front 6

Organisms generally involved in polymicrobial infections

Back 6

1-ANA
2- Facultatvie ANA
3- Aerobes

Front 7

Final electron acceptor in respiration

Back 7

Usually oxygen, but can also be an inorganic compound

Front 8

Final electron acceptor in anaerobic respiration

Back 8

NO3
SO4
CO2

Front 9

Final electron acceptor in fermentation

Back 9

organic compound like acid or alcohol

Front 10

Define moderate and strict anaerobe

Back 10

Moderate- unable to multiply in more than 2-8% O2
Strict- cannot multiply in more than 0.5% O2

Front 11

composition and percentage in air incubator

Back 11

21% O2
0.03% CO2

Front 12

composition and percentage in CO2 incubator

Back 12

15% O2
5-10% CO2

Front 13

composition and percentage in Anaerobic system

Back 13

0-0.5% O2
5-10% H2
5-10% CO2
80-90% N2

Front 14

describe the specific effects free radicals can have on molecules that they come in contact with, and how many free radicals are produced each day in a typical human.

Back 14

-Accumulation of damage from oxygen stealing electrons is called oxidative stress
- 1 trillion oxygen radical generated every day

Front 15

describe what happens to our bodies ability to fight free radicals as we age

Back 15

our ability to fight free radicals decreases, and we make more as we age

Front 16

give the name of the body’s natural defense against oxidative stress and list 3 examples and where they are found outside the body

Back 16

Anti-oxidants are the bodys natural defense
-Exogenous sources of anti-oxidants are vitamins A, C, E, found in fruits and vegetables, and also melatonin

Front 17

List and describe, in detail, two reasons why O2 is so toxic to humans and to anaerobes

Back 17

Oxygen produces Free radicals like superoxide radical
- and toxic O2 derivatives like H2O2 and a Hydroxyl radical
- Radicals cause damage to cellular components by denaturing protein, denaturing/mutating DNA and RNA, and damaging the phosholipid bilayer
-toxic to anaerobes because they have fewer enzymes and pathways to deal with free radicals and toxic by products

Front 18

Enzyme content for O2 detoxification in strict aerobes and Facultative anaerobes

Back 18

Catalase and Superoxide dismutase

Front 19

Enzyme content for O2 detoxification in Strict anaerobes

Back 19

none

Front 20

Enzyme content for O2 detoxification inmicroaerophile

Back 20

Small amounts of catalase and SOD

Front 21

Enzyme content for O2 detoxification in aerotolerant

Back 21

SOD

Front 22

Give the chemical reaction a cell can use to eliminate toxic hydrogen peroxide

Back 22

2H2O2---(catalase)-->2H2O + O2

Front 23

List 6 indications of anaerobic infections

Back 23

1- infection in close proximity to a mucosal surface
2- infection persists despite aminoglycoside therapy
3- foul odor, and or large quantity of gas
4- black color or brick-red florescence
5- microscopic sulfur granules
6- unique gram stain

Front 24

Define PRAS in terms of transport and culture media

Back 24

Pre-reduced anaerobically sterilized transport media
- oxygen has been removed or reduced
-shipped and stored in sealed anaerobic pouches

Front 25

Explain the GAS-PAK system

Back 25

Sodium borohydride tablet produces H2
- 2H2 + O2----(palladium)-->2H2O - this reduces O2 concentration
- NaHCO3 + citric acid tablet produce CO2- increases % from .03 to 5-10%
- Methylene blue indicator strip (if your white your alright)

Front 26

Explain aerotolerance test and what organisms grow in which chambers

Back 26

- duplicate plates put in ANA and CO2 then checked for growth at 24-48 hrs
- Strict anaerobe will only grow in ANA
- Facultative and capnophile will grow in ANA and CO2

Front 27

Explain the special potency disks

Back 27

organisms are either resistant or susceptible to
- Vancomycin, Colisitin, Kanamycin, or Sodium Polyanethol Sulfonate (SPS)
or Tolerant or susceptible to
-Nitrate or Bile disks

Front 28

Spot tests/plate rxns for anaerobes

Back 28

indole, catalase, motility, lecithinase and lipase rxns

Front 29

Biochemical ID system for anaerobes

Back 29

API

Front 30

what is GLC

Back 30

Gas liquid chromotography
- produces a chemical fingerprint

Front 31

List the G pos anerobic Bacilli (C BLEAP)

Back 31

Clostridium (sporeformer0
Bifidobacterium
Lactobacillus
Eubacterium
Actinomyces
Propionibacterium

Front 32

List the G pos anerobic cocci

Back 32

Anaerococcus
Peptoniphilus
Peptococcus niger
Peptostreptococcus

Front 33

List the G neg anerobic cocci

Back 33

Veillonella

Front 34

List the G neg anerobic bacilli

Back 34

Bacteroides
Fusobacterium
Porphyromonas
Prevotella

Front 35

Bacteroides- NF sites

Back 35

Intestinal tract, oral cavity, and vagina

Front 36

Bacteroides Lab ID

Back 36

Resistant to K, V, and CL
Bile tolerant
Isolated on KVLB
GS- short G neg pleiomorphic rods

Front 37

NF sites for Fusobacterium

Back 37

URT, intestinal tract, urethra

Front 38

Lab ID for fusobacterium and species

Back 38

Fusobacterium nucleatum GS- long thin tapered rods
Fusobacterium mortiferum GS- globular swelling and bizarre shape

Front 39

NF sites for Porphyromonas and Prevotella

Back 39

Oral cavity

Front 40

Lab ID for Porphyromonas and Prevotella

Back 40

Both are bile sensitive
Prevotella melaninogenica
- On KVLB pigment is enhanced (brown to black)
- produces brick red fluorescence under woods lamp
Porphyromonas asaccharolytica
- N/G on KVLB
- produces brown to black pigment on SBA
- produces fluorescence under woods lamp

Front 41

NF sites for Clostridium species

Back 41

Intestinal tract of humans and animals

Front 42

explain Gas gangrene and organisms that cause it

Back 42

-AKA myonecrosis
- caused by C. perfringens, and C. histolyticum
- Alpha toxin is produced and caused tissue necrosis. Cuts off blood supply and O2 conc. increasing CO2 conc. and organism thrives

Front 43

Treatment for gas gangrene

Back 43

-Debridement of necrotic tissue
- hyperbaric O2 chamber with 3 atm of pressure
- antisera against alpha toxin
- antimicrobials

Front 44

Explain C. tetani origin and toxin stuff

Back 44

Exogenous infection from spores that are deposited in the soil from animal poop
- CNS toxin produced causes continued excitation of motor neurons
- most common cause of neonatal death in underdeveloped countries
- 100 cases/year usually in inadequately immunized persons and drug addicts

Front 45

Details of C. botulinum

Back 45

-botulinum means sausage
- Botulism comes from ingestion of preformed toxin from canned goods
most poisonous substance know
- neurotoxin binds to cranial nerves and prevents release of Ach
- death by paralysis of diaphragm
- newborns are very susceptible which is why you dont give them honey

Front 46

Details of C. difficile

Back 46

-Antibiotic associated enteritis
- pseudomembrane colitis
- common following antimicrobial therapy
- common cause of nosocomial infection
Toxin A; enterotoxin
Toxin B; cytotoxin

Front 47

GS of C. tetani

Back 47

G pos rods that look like tennis raquets (golf clubs really)

Front 48

GS of C. perfringens and difficile

Back 48

look like box cars, may be gram variable if culture plate is older than 6 hrs

Front 49

C. perfringens lab ID

Back 49

V susceptible
K susceptible
Cl resistant
no growth on KVLB
Lecithinase +
Lipase -

Front 50

EYA results for C. botulinum

Back 50

Lecithinase -
lipase +

Front 51

EYA resuslt for Bacteroides fragilis

Back 51

lecithinase -
lipase -

Front 52

EYA resuslt for Fusobacterium nucleatum

Back 52

lipase +

Front 53

EYA resuslt for P. acnes

Back 53

lecithinase -
lipase +

Front 54

Egg yolk agar characteristics

Back 54

Lecithin turns into white opaque precip if LECITHINASEis present
- free fats give a Mother of Pearl sheen if LIPASEis present (turns to glycerol and fatty acids)
- proteins give clearing around colonies if PROTEOLYTIC ENXYMES are present

Front 55

Explain reverse CAMP rxn

Back 55

S. agalactiae in the middle and perpendicular line of C. perfringens gives enhanced zone of hemolysis

Front 56

explain direct Nagler test

Back 56

EYA with anti-toxin zig-zagged on one side and C. perfringens perpendicular to the zig zags
- after 24 hrs C. perfringens will give a lecithinase precip rxn in area where anti toxin isn't present

Front 57

Hemolysis of C. perfringens

Back 57

gives inner zone of complete hemolysis
-outer zone of partial

Front 58

CCFA

Back 58

cycloserine, cefoxitin, fructose agar
- used in direct plating of stool samples to ID C. difficile

Front 59

list 3 etiological factors in the development of acne

Back 59

increased sebum production
hypercornification of follicle ducts
altered metabolism of cutaneous microflora such as P. acnes

Front 60

explain how P. acnes is involved in the formation of blackheads

Back 60

it produces lilpases that hydrolyze sebum triglycerides to FFA.
-FFA and their oxidant products may be involved in the formation of blackheads
- P. acnes may also produce and release exocellular enzymes or histamine and fatty acids

Front 61

list two other organism that are also normal flora of the sebaceous follicles

Back 61

staphylococci and yeasts

Front 62

NF sites of Actinomyces israelii

Back 62

oropharynx and vagina

Front 63

NF sites for P. acnes

Back 63

predominant NF on skin and also NF of colon

Front 64

Lab ID for P. acnes

Back 64

-produces lipase
- GS- G pos rods that look like diptheroids
- Cat pos
- Spot indole pos

Front 65

Lab ID for A. israelii

Back 65

-causes actinomycosis which produces slow growing abscesses
- causes LUMPY JAW
- GS- G pos branching filamentous
- produces sulfur granules
- slow growing, takes 1-2 weeks

Front 66

Characteristics of Mobiluncus

Back 66

NF of vagina
- may play a role in bacterial vaginosis
- if lactobacillus conc. goes down then Mobiluncus and G. vaginalis conc increase and cause bacterial vaginosis
- GS- curved G pos rods

Front 67

NF sites for Bifidobacterium and Eubacterium

Back 67

GI tract

Front 68

NF sites for Peptostreptococcus anaerobius

Back 68

oral cavity, colon, vagina

Front 69

Characteristics of Peptostreptococcus anaerobius

Back 69

-generally not pathogenic
- GS G pos cocci/chains
- sensitive to SPS (sodium polyanethol sulfonate)

Front 70

Human bite wound aerobic bacteria

Back 70

S. aureus
Eikenella corrodens

Front 71

Human bite wound anaerobic bacteria

Back 71

Peptostreptococcus
Prophyromonas
Prevotella
Fusobacterium

Front 72

Animal bite bacteria

Back 72

Pasturella muticoeda
S. aureus

Front 73

NF sites for veillonella

Back 73

oral cavity
-causes infectionsin head, neck, and in dental surgery
GS- small g neg cocci

Front 74

Identify the major divisions of mycobacteria and the species associated with each

Back 74

Mycobacterium that cause tuberculosis
- M. tuberculosis
- M. bovis
- M. africanum
NonTuberculous Mycobacteria (NTM)
- M. avium-intracellulare complex
- M. leprae-- causes leprosy

Front 75

Define MAC in terms of mycobacterial species and how its affect individuals with AIDs

Back 75

M. avium-intracellulare complex- (MAC complex) opportunistic pathogen in AIDS patients-
- 30-50% infection rate
- disseminated infection can occur in all organs

Front 76

compare the cell wall of mycobacteria to Gram negative and Gram positive bacteria

Back 76

Has a cell wall made of MYCOLIC ACID, ARABINOGALACTAN (arabinos and galactose), and then a peptidoglycan layer

Front 77

List and explain the advantages and disadvantages of the mycobacterial cell wall

Back 77

-prevents dessication
-organism can survive 6-8 months unless exposed to UV light
- protects organism from host defenses like lysozymes in macrophages
- porin proteins help in antimicrobial resistance
- down side is it makes it hard for the cell to get nutrients
- takes 20 hrs for M. tb to reproduce

Front 78

Compare the generation time of M. tuberculosis, rapid and slow growers to that of E. coli

Back 78

M. tb= 20 hrs
Slow growers= 24 hrs
Rapid growers= 12 hrs
E. coli= 20 minutes

Front 79

List the three staining procedures that are used for mycobacteria

Back 79

Zeihl-Neelsen stain
Kinyoun stain
Auramine-rhodamine flurochrome

Front 80

describe the steps of the Zeihl-Neelsen stain

Back 80

-Hot acid fast stain
-Heat with bunsen burner until steams then let sit for 5 minutes
- primary stain is Carbolfuchsin (red color)
- decolorize with 0.5% HCL/ 70% ethanol - 3 min
- counterstain with methylene blue for 1 min
- mycobacteria get a reddish bacillus
- must look at 300 fiels or 15 minutes to call negative

Front 81

Describe the steps of Kinyoun stain

Back 81

-Cold acid fast stain
- same as Zeihl-Neelsen, but not heated
- must look at 300 fields or 15 minutes to call neg

Front 82

explain the advantage of the auramine-rhodamine fluorochrome stain.

Back 82

-more sensitive than carbofuchsin stains
-requires fluorescence microscope or filter and is viewed at 40x

Front 83

Explain the basis of the Runyon classification scheme used for NTM. Name and define the two categories of pigment production used to classify mycobacteria

Back 83

-4 groups based on pigment and growth rate
pigment classifications are
- photochromogens- produce pigments only in light
- scotochromogens- produce pigments in light or dark

Front 84

Pigmentation and best growth areas of M. tuberculosis

Back 84

-non-pigmented
- grows best in upper portions of lungs